Swimmer&#39;s propulsion aid



March 23, 1954 J. K. LA TRELL SWIMMERS PROPULSION AID 5 Sheets-Sheet 1 Filed April 14, 1949 BYG M ATTORNEY.

J. K. LA TRELL SWIMMERS PROPULSION AID March 23, 1954 5 Sheets-Sheet 2 Filed April 14, 1949 Jim/a K- LfiZELL,

BY m

March 23, 1954 J. K. LA TRELL SWIMMERS PROPULSION AID Filed April 14, 1949 5 Sheets-Sheet 3 ATTORNEY.

March 23, 1954 J. K. LA TRELL 7 2,672,629

SWIMMERS PROPULSION AID Filed April 14, 1949 5 Sheets-Sheet 4 CIICKK $979544,

1N VENT OR.

ATTORNEY.

March 23, 1954 J. K. LA TRELL SWIMMERS PROPULSION AID 5 Sheets-Sheet 5 Filed April 14, 1949 INVEN TOR. a w

ATTORNEY.

Patented Mar. 23, 1954 UNITED S TATES PATENT OFFICE SWIMMERS PROPULSION AID Jack K. La Troll, Glendale, Calif.

Application April 14, 1949, Serial No. 87,537

This invent-ion relate-c to means to be used by a swimmer as an aid to propelling himself through the water, more particularly to such means to be worn on a swimmers feet, and to a method of making the same.

It is an object of this invention to provide an improveddevi'ce for this purpose.

It is another object of this invention to provide sucha' device which is light, strong and durable, and is comfortable to'the wearer.

- It is another object of this invention to provide such a device adapted to be fabricated in a simple and economical manner.

It'is another object of this invention to provide such a device adapted to be fabricated of readily available sheet material, reeniorced in a novel manner.

It is another object of this invention to provide a device of the character described in graduated proportions to accommodate differently sized wearer's feet, and which may be readily adjusted to an intermediate size. I

It is another object of this invention to provide a novel method of making a device of the character described.

This invention possesses many other advantages, and has other objects which may he made more easily apparent from aconslderation ofsevoral. embodiments of the invention. For this purpose there are shown two forms in the drawings accompanying and forming part of themesent specification. These forms, which illustrate the general: principles of the invention, will now be described indetail; but it is to bennderstood that this detailed description is not to be' taken in a limiting sense. since the scope of the invention is best defined by the appended claims.

r In the-accompanying drawing-s:

Figure l is a perspective view showing a pair of devices incorporating feature of the invention, inusebya swimmer;

Figure 2 .is a top plan view of one of the devices of Figure 1, seen as looking down on Figured, and" partly broken away to show the construction;

Figure 3 is a longitudinal section, taken substantially as indicated by line 3-4 of Figure 2; Figure! is a detail section, taken substantial- 131 as indicatedby line 4-4 of Figure3;

Figure 5v is a transverse section, taken "substandaily as indicated by line 5--'5 of Figure 3;

Figure 6 is a detail section, taken substanitally as indicated by line 6-43 of Figure 2;

Figure 71s a bottom-plan view, seen as-loolring from below m nicure 3-, and partly broken away toshovsthe-construction;

17 Claims. (01. 9-21) Figure 8 is a developed top view 01 the body at an intermediate stage in its fabrication;

Figure 9 is a corresponding bottom view,'-partly broken away to show the construction;

Figure 10 is a top plan view of the body frame;

Figure 11 is a side elevation thereof, seen as indicated by the arrow marked H of Figur 1 0;

Figure 12 is a top plan view partly in section of a modified form of the device:

Figure 13 is a bottom plan view thereof;

Figures 14 and 15 are-sections taken 'substan-- tially as indicated by the correspondingly numbered lines of Figure 12;

Figure 16 is a detail section taken substantially as indicated by line Iii-l6 of Figure 12';

Figure 1'? is a delevoped' top-view, showing the body of the device of Figure12, at an intermediate stage in its fabrication, partly broken awayto show the construction;

Figure 13 is a developed bottom View, showing the said body at another stage in its fabrication; and

Figures 9 and '20 are detail sections, taken substantially as indicated by the correspondingly numbered lines of Figure 18.

Referring to that form of the invention shown in Figures 1 to 11 of the drawings, the device comprises a body or shoe 1!! formed of apair of similarly shaped pieces I l and 12 of flexible sheet material, which may be rubberized woven fabric, appropriately secured together in'super-posed relation. A bifurcated frame member 13 of resilient material, such for example as wire of suitable characteristics, secured between the pieces H and l 2, cooperates therewith to form the foot accommodating pocket M as well as maintaining the proper body configuration by tensioning the side and forward body portions to transversely arch the body ill so that it provides a concave 0r cupped surface l0-a facing in the same direction as the soles of the wearers feet.

This frame I3 as best shown in Figures 10 and and 11, comprises a central reentrant portion l3-a including a pair of generally parallel sections 15 and Id of the frame joined at their inner ends by a curvedisection ll and at their outer ends to the diverging arms 19 and 20 respectively with" pocket It of-thecompleted'body it, as shownby Figures 3 and 5. Further, the body II! has side portions Ill-b and Ill-c on opposite sides of the pocket I 4 as well as a portion I Il-d forwardly therefrom. The edges of the portion IB-d converge forwardly to an apex III-e. The frame I3 is secured within the body It between the pieces H and I2 so that the arms I9 and 20 are confined respectively adjacent the outer edges ill-b and III-c, sections I5, I6 and I1 being confined about the perimeter of the pocket I4. As just pointed out, the body pieces I I and I2 are so proportioned as to provide substantial fulness of material between the frame sections I5 and I 6 to form the pocket I4. On the other hand, the pieces II and I2 are so proportioned that the frame arms I9, 23 and sections l5, I6 are confined under tension by the body portions IU-b and III-c, arms I9, 20 being flexed inwardly, and sections I5, I6, I1 downwardly from their initially formed configuration shown by the full lines of Figures 10 and 11, to that indicated by the broken lines. In this way the body is resiliently maintained transversely arched.

The frame I3 renders the body It quite resistant to flexing, particularly in a longitudinal direction, but as clearly shown in Figure 7, the arms I9 and terminate some distance short of the apex Ill-e of the body ID so that the outer end of the forward portion I Il-d is unrestrained thereby. However, as will be pointed out shortly hereinafter, means are provided for restricting the flexing of this forward portion Ill-d.

Since the swimmer will, in general, do considerable walking while wearing the devices, it is desirable to protect the lower faces thereof from abrasion particularly since the surfaces walked on will usually comprise highly abrasive materials such as sand, sharp rocks, etc. For this purpose, a wear strip or sole 22 is provided on the bottom of the foot accommodating pocket I4, it being understood that when the users weight rests on the device the frame 13 will flex, allowing the body ID to flatten out so that the undersid of the pocket I4 rests on the ground.

To protect the outer edge portions of the body from such abrasion a binding tape 23 is provided about the edges of the body I!) (see Figure 6). That portion of the sole 22 ahead of the frame cross piece I1 serves to accommodate a resilient stiffener 24 which may be of a suitable plastic, for restricting flexure of the forward portion I Ii-d as previously discussed. The resistance to iiexure of this portion Ill-d may be readily altered by using different thicknesses and/or materials for the stiffener 24.

As clearly shown in Figure 3 and 11, the arms l9 and 20 of the frame I3 are joined in spaced relation to the sections I5 and I6 respectively by short upwardly extending arm 25 and 26 which are positioned just behind the body III. An elastic strap 28 is adjustably secured at its opposite ends respectively to arms 25 and 26 as by the aid of buckles 29 and 33, and is adapted to extend about the heel of the wearer to retain the foot in pocket I 4, as shown in Figure 3.

Means are provided for adjusting the width of the outer end of the pocket I4 to accommodate the users foot (see particularly Figures 4 and '7) Thus, a pair of eyeletted openings 3I and 32 are provided in each of the body side portions Ill-b and III-c adjacent the rear end thereof, and

a similar pair of openings 33 and 34 are providedin the lower body piece I2 within the pocket I4 and adjacent the edge thereof. A lacing or cord 35 is roved through the adjacent pairs of eyelets 3 I, 32 and 33, 34, appropriately tensioned and tied (see Figure 2). By altering the tension in the lacings 35, the effective size of the pocket I4 may be varied.

In constructing the device, sheet material is out or otherwise formed to provide a pair of pieces, as H and I2, Figures 8 and 9 respectively, having the general configuration of the completed body I3 :but wider across the rearend, as previously discussed. That piece, Figure 9, which is to form the bottom piece I2, then has the central sole or wear piec 22 attached by rows of stitching respectively along the longitudinal edges and the inner pairs of openings 33 and 34 are formed. The pieces II and I2 are then joined in superposed relation by rows of stitching 36 and 31 extending respectively along the opposite edges of the pieces from the rear and terminating a short distance from the apex IIl-c leaving an opening through which the frame I3 may be inserted. The pieces I I and I2 are also joined in their central areas by a line of stitching 39 having the pattern of the frame sections I5, I6, I 1 but spaced somewhat further apart, as previously discussed. This line of stitching 33 serves as a stop to position the frame I3, the resulting fullness of the material when the frame I3 is in place forming the pocket I 4.

After the frame I3 has been inserted, the exterior pairs of eyeletted openings 3|, 32 are formed and the stiffener 24 is inserted. The lines of stitching 36 and 31 are then completed to the apex Ill-e and the binding tape 23 applied. The stitching 40, which secures the tape 23, extends along the inside of the frame arms I9 and 26, and thus cooperates with the stitching 36 and 31 to hold the lower portion of the frame I3 in place. Similarly, a row of stitching 4| is provided exeriorly of the frame sections I5, I6, I1 which cooperates with the stitching 39 to hold the reentrant portion I3-a of the frame I3 in place. If desired, binding tape 42 may be provided on the rear edges of the body pieces I I and I2.

An additional row of stitching 43 is provided across the inner end of the pocket I4 and serves to prevent injury to the users toes by providing a cushion, which prevents them striking the end section I1 of the frame I3.

In use, one of the devices is mounted on each of the users feet, the pocket I4 accommodating the fore part of the foot, the strap 28 retaining the device in place on the foot. The transverse curvature of the body II) will cause the'device to strongly resist rearward or downward movement" of the feet so that a force substantially'greater than that caused by movement in the reverse di-' rection' will be exerted, urging the swimmer ahead or upwardly as the case may be. This force is substantially augmented by the forward extension ID-cl.

The modified form of the invention shown Figures 12 to 20 is quite similar to the device just described. Thus, it comprises a body 50 formed of two pieces of flexible sheet material 5| and 52 secured in superposed relation and confining between them, a resilient frame 53' having diverging arms 54 and 55 and reentrant central portion 56. The central portion 53 cooperates with the body pieces to form a, foot accommodating pocket 51, the arms 54 and 55 tensioning the body side portions 50-11 and 50-22, and maintaining the body transversely curved as before. In this case the forward portion Ell-c ofthe body is formed by a separate piece of re-,. silient sheet material, such for example as cor-.

rugated rubber of suitable thickness; secured between thebody pieces :5! and .52. The edges of this portion converge forwardly toan: apex iii-d which is offset from'the center line of J the body. Thus. the device is. for *useon the right or left-foot in accordance with thecposition of the apex. SB-d with respect-to the centerline.

That portionof the portion 59-11 immediately adjacent the body 5U is similarly transversely curved, so that the resistance-to. flexure of the the portion 59--d-when thesuser is'making'apropolling-stroke isgreaterthan in a return or idling stroke.

The method of making this iormof the device is quite similar to that of the. preceding form, in thatthe two bodypieces '51 andiiz'are secured together along their. opposite side edgesand in a central poclnet'forming:zone'v so that the frame 53 may be "inserted through an open: endiof/the body .511, as before. However, in this case the body pieces 51 and 5.2 are initiall secured together along their sideedges with the wrong side out, as shown in Figure: 17, and then "turned right side out for the succeeding steps, as shown in" Figure 18. In this; way. no new edges of'the ma terial or the stitching is exposed and the need of a binding tape is avoided. Furthermore, the pieces 5! and 52 may have hems or integral facings formed on their transverse edges.

Thus; referring to Figure 17 the body top piece 51. has the hems 54-11, 51-!) respectively at'its opposite ends. secured by lines of transverse stitching before the piecesare brought together. This piece isshown as broken away so that the bottom piece .52 is partly visible. This piece 52 also has the horns Si -a, 524) turned and stitched, the eyeletted openings 58- formed and the sole or wear piece 59 attached, before attachment to the top piece 51. The partly finished pieces 5| and 52 are superposed and secured together by stitching 60 along their side edges, the resulting body 56 being turned insideout so that thefacings and stitching are inside, see Figures 'l-snand 20, and the sole 59 outside. The stitching (H to define the pocket 51 is thenapplied, the frame 53 inserted through the open end of the body 58 opposite the pocket 51 and the structurecompleted in a manner similar tothat previously discussed.

Iiolaim:

1'. In a swimmers aid.:. a body comprising a pair of superposed layers of sheet material; a resilient frame secured between said layers and having a central reentrant portion cooperating therewith to form a foot accommodating pocket;

said body having extensions on opposite sides of said pocket; means joining said layers along their optside edges; resilient members attached to said layers adjacent said edges and cooperating with said central portion to tension said body extensions; said body having a wear piece on the bottom exterior of said pocket; and a strip secured to said body and embracing said edges.

2. In a swimmers aid: a body of flexible material; and a frame having a central reentrant portion cooperating with said body to form a foot engaging pocket; said body having side portions; said frame including resilient arms engaging said side portions and cooperating with said reentrant portion to tension said side portions.

3. In a swimmers aid: a body of flexible material having a foot accommodating pocket and portions on opposite sides thereof; and a resilient frame secured to said body and providing a centra1 portion defining the perimeter of said pocket;

ill]

said frame having side arms cooperating with terialhaving a foot accommodating pocket and portions on opposite sides of said pocket; 2. re-- silient'frame secured in said body and having a.

central portion engaging said body between said. side portions; said frame having side arms disposed in a difierentplane than said central portion and cooperating with said central portion to engage and tensionsaid side portions of said body; and means connected with said frame for retaining the users foot in said pocket.

.6. In a swimmers' aid: 2. body having a portion adapted for engaging the foot; said body including portions extending on opposite sides of the foot as well as forwardly therefrom; and resilient means including pairs of opposed mem-- bers disposed one above the other and in later ally spaced relation to one another for engaging and iioaintahiing a part of said foot engaging portion and a. part of saidforwardly extending portion transversely arched.

'7. In a swimmers aid: a body of flexible sheet materialadapted to be mounted'on the foot and to extend onopposite sides of the. foot as well as forwardly therefrom; and a resilient frame opposing deformation of said body; said frame including portions in different planes engaged with and extended along-marginal and intermediate portions. of said body and terminating at. a pointtspaced fromzthe forward'end portion of said body to permit flexing of said forward end portion.

8. In a swimmers: aid: a body adapted for mounting on the foot; said body extending on opposite sides of the foot and having a flexible forward portion; a. resilient member for impart ing limited resistance to flexure of said forward portion; means securing said member on said forward portion; and a frame having portions in diiferent planes secured to said body.

9. In a swimmers aid: a body adapted for mounting on the users foot comprising a pair of superposed layers of flexible material; a frame having resilient members disposed in different planes between said layers for resiliently maintaining a predetermined configuration of said body with portions of said layers spaced apart to receive the foot; and means securing other portions of said layers together and extending about said frame for securing the frame in the body.

10. In a swimmers aid: 9. body comprising a pair of superposed layers of flexible material; a resilient frame interposed between said layers and. having a central reentrant portion cooperating with said layers to form a foot accommodating pocket; portions of said layers extending on opposite sides of said pocket as well as forwardly therefrom; a pair of diverging arms secured to and extending along margins of said side portions; said arms cooperating with said central portion to tension said side portions as well as a part of said forward portion; and means securing said layers and said frame in assembled relation.

11. In a swimmers aid: a body of flexible material; a resilient frame having a, central reentrant portion cooperating with said body to form a foot accommodating pocket; said body having portions extending on opposite sides of said pocket as well as forwardly therefrom; said frame including a. pair of diverging arms attached to said body; said arms extending from the rear of said frame and cooperating with said central portion to maintain the extended portions of the body tensioned; the rear of said frame having spaced portions projecting from the body; and means extending between and joined to said projecting portions of said frame for engaging the users heel to retain the users foot in said pocket.

12. In a swimmers aid: a body of flexible sheet material having a rearwardly opening pocket for accommodating the fore part of the foot; heel engaging means for retaining said foot in said pocket; said body having portions extendin on opposite sides of the pocket as well as a forward portion; and a resilient frame extending along and secured to opposite sides of said pocket as well as along and in contact with said side portions of said body for maintaining said side portions in extended position and transversely arched.

13. In a swimmers aid: a body of flexible sheet material; and a resilient bifurcated frame having a portion defining a rearwardly directed opening cooperating with the body to form a foot accommodating pocket intermediate side edges of the body; said frame including arms extending forwardly from said opening beneath the plane of said portion of the frame and engaging portions of the body on opposite sides of said pocket for maintaining the body in extended configuration.

- 14. In a swimmers aid: a body of flexible sheet material; and a resilient bifurcated frame having a portion defining a rearwardly directed opening cooperating with the body to form a foot accommodating pocket intermediate opposite marginal portions of the body; said frame including resilient arms joined to said portion of said frame; said arms extending below the plane of said portion of the frame and engaging portions of said body on opposite sides of said pocket.

15. In a swimmers aid: 9, body comprising a pair of superposed layers of sheet material; a resilient frame secured between said layers and having a central reentrant portion cooperating therewith to form a foot accommodating pocket; said body having portions on opposite sides of said pocket; means joining said layers along their outer edges; resilient members on said frame secured to said side portions and cooperating with said central portion of the frame to tension said side portions of the body; a wear piece on the exterior of said pocket; and means defining said outer edges and protecting said joining means from external abrasion.

16. In a swimmers aid: a body comprising a pair of superposed layers of sheet material; a resilient frame secured between said layers and having a central reentrant portion cooperating therewith to form a foot accommodating pocket; said body having portions on opposite sides of said pocket; means joining said layers along their outer edges; said frame having resilient members attached to said layers adjacent said edges and cooperating with said central portion to tension said side portions of said body; said body having a wear piece on the exterior of said pocket; and a strip secured to said body embracing said edges.

17. In a swimmers aid: a body of flexible material adapted to be mounted on a foot of a swimmer; side portions on said body; and a frame having a portion engaging said body and cooperating therewith to form a foot-receiving pocket; said frame including resilient arms; disposed below the plane of said portion of said frame engaging and tensioning said side portions.

JACK K. LA TRELL.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,202,083 Mee Oct. 24, 1916 1,494,452 Waldron et a1 May 20, 1924 1,571,462 Waldron et a1. Feb.2, 1926 1,625,730 .Lake Apr. 19, 1927 1,788,013 Christianson Jan. 6, 1931 2,078,068 Eustis Apr. 20, 1937 2,099,973 De Corlieu Nov. 23, 1937 2,321,009 Churchill June 8, 1943 2,423,571 Wilen July 8, 1947 

